than 13,000 households across Canada. This cohort continues to be
followed longitudinally, with data collected at each 2-year cycle.
In addition, each cycle includes newly born children ages 0–23
months who are followed until they are ages 4–5 years, to gain addi-
tional data on early child development. The 5th survey cycle was
completed in 2002–03, and the data from this cycle became available
in early 2005 (Statistics Canada 2005).
The NLSCY includes several longitudinal and cross-sectional sam-
ples, and the longitudinal samples are representative of the initial co-
hort of children. The information resulting from the NLSCY is widely
used to inform government administrators and policymakers, as well
as university researchers and scientists.
Social Gradients of Vulnerability
One of the major findings from the NLSCY is that—
Children in all socioeconomic classes in Canada are “vulnerable” (that
is, they have a learning or behavioral problem).Figure 1 illustrates this finding for children ages 4–6 years.
The specific data (Mustard and McCain 2002) are as follows:- Low socioeconomic class (–1.5 socioeconomic status, or SES, on
the figure)—almost 35 percent of children ages 4–6 years out-
side of the province of Ontario are vulnerable. Within Ontario,
the percentage is even higher. - Middle socioeconomic class (–1.0–1.0 SES)—15–25 percent or
more of children are vulnerable. - Affluent socioeconomic class (1.5 SES)—more than 10 percent
of children are vulnerable.
Number of Children
The number of vulnerable children is an important data point. In
Ontario, for example, which has 300,000 children ages 4–6 years,
75,000 of them across all social classes are vulnerable (McCain and
Canada: Longitudinal Monitoring of ECD Outcomes 171